Digital Voice: No ring with third-party VOIP adapter online

[PeteCress]

Just switche over to Verizon FIOS Digital Voice.

For a bunch of years, I have had a LinkSys SPA3102 VOIP adapter hooked up to the system. .... This adapter handles all outgoing non-800 calls and routes them to a third-party VOIP provider (CallCentric.com).

Incoming calls have always been via Verizon - POTs before this month, FIOS Digital Voice as of now.

Coincident with the changeover to Digital Voice, my phone stopped ringing on incoming calls.  ... Everything else worked, but no rings.

The rings are coming in from Verizon, but the SPA3102 is, somehow, squashing them - but only under FIOS Digital Voice; everything worked A-OK with POTS.

Remove the 3102, and everything works.

Are my third-party VOIP days over? .... Or might there be a workaround ?